I was hit again by this today. In the current state, Netdata is completely broken when it tries to send an email. I have to manually edit the systemd file, which is clobbered by any apt upgrades. I had unattended-upgrades on a bit aggressively and today Netdata broke again, as 1.19.0-3 was pulled in. Because the systemd file is (correctly) not flagged as a config file, it was replaced. Then as soon as netdata tried to send an email, it was broken again.
In my case I am using postfix instead of exim, but the issue is similar. Netdata needs r/w access to the mail queue to send mail. This was originally brought up in #851852. It seems it was fixed in 1.5.0 (?) and has regressed at some point since then. Thank you for maintaining this package!
